Conclusions from EcologicalRisk Assessment forRiskAssessmentforRodenticidesRiskAssessmentforRodenticidesPresentation to the SAPNovember 29th, 2011Dr. Edward OdenkirchenDr.EdwardOdenkirchenEnvironmental Fate and Effects Division1Lines of evidence•Toxicity•Standard test species•Risks of Mortality to Primary Consumers•Single and multiple day dose based RQ•Dietary RQs•Days feeding and mass of bait consumed to reach lethal threshold•Risks of Mortality to Secondary ConsumersRisksofMortalitytoSecondaryConsumers•Single and multiple day oral dose based RQ•Theoretical prey concentrations•Empirical prey concentrations•Dietary RQDietaryRQ•Secondary feeding studies•# prey animals consumed to reach lethal threshold•Reported Incidents of Mortalityy•Investigation of primary and secondary route association•Investigation of land use association (urban/suburban vs. rural)•Survey of exposure data from open literature2RQs andOpportunityIncident DataConclusionChemicalPrimaryRiskSecondaryRiskPrimary SecondaryUrban/SuburbanPrimary SecondaryBirdsBrodifacoumDifethialoneNo dataWarfarin (0.025%)Warfarin (0 054%)Warfarin(0.054%)ChlorophacinoneDiphacinoneBromethalinNo data No data No dataMammalsBrodifacoumDifethialoneWarfarin (0 025%)NodataNodataWarfarin(0.025%)Warfarin (0.054%)No data No dataChlorophacinoneDiphacinoneBromethalinNo data No data3AllevidencesuggestsriskPredominantevidenceofriskEquivocalevidenceofriskAllevidencesuggestslowriskRQs andOpportunityIncident DataConclusionChemicalPrimaryRiskSecondaryRiskPrimary SecondaryUrban/SuburbanPrimary SecondaryBirdsBrodifacoumDifethialoneNo dataWarfarin (0.025%)Warfarin (0 054%)Warfarin(0.054%)ChlorophacinoneDiphacinoneBromethalinNo data No data No dataMammalsBrodifacoumDifethialoneWarfarin (0 025%)NodataNodataWarfarin(0.025%)Warfarin (0.054%)No data No dataChlorophacinoneDiphacinoneBromethalinNo data No data4AllevidencesuggestsriskPredominantevidenceofriskEquivocalevidenceofriskAllevidencesuggestslowriskRQs andOpportunityIncident DataConclusionChemicalPrimaryRiskSecondaryRiskPrimary SecondaryUrban/SuburbanPrimary SecondaryBirdsBrodifacoumDifethialoneNo dataWarfarin (0.025%)Warfarin (0 054%)Warfarin(0.054%)ChlorophacinoneDiphacinoneBromethalinNo data No data No dataMammalsBrodifacoumDifethialoneWarfarin (0 025%)NodataNodataWarfarin(0.025%)Warfarin (0.054%)No data No dataChlorophacinoneDiphacinoneBromethalinNo data No data5AllevidencesuggestsriskPredominantevidenceofriskEquivocalevidenceofriskAllevidencesuggestslowriskRQs andOpportunityIncident DataConclusionChemicalPrimaryRiskSecondaryRiskPrimary SecondaryUrban/SuburbanPrimary SecondaryBirdsBrodifacoumDifethialoneNo dataWarfarin (0.025%)Warfarin (0 054%)Warfarin(0.054%)ChlorophacinoneDiphacinoneBromethalinNo data No data No dataMammalsBrodifacoumDifethialoneWarfarin (0 025%)NodataNodataWarfarin(0.025%)Warfarin (0.054%)No data No dataChlorophacinoneDiphacinoneBromethalinNo data No data6AllevidencesuggestsriskPredominantevidenceofriskEquivocalevidenceofriskAllevidencesuggestslowriskRQs andOpportunityIncident DataConclusionChemicalPrimaryRiskSecondaryRiskPrimary SecondaryUrban/SuburbanPrimary SecondaryBirdsBrodifacoumDifethialoneNo dataWarfarin (0.025%)Warfarin (0 054%)Warfarin(0.054%)ChlorophacinoneDiphacinoneBromethalinNo data No data No dataMammalsBrodifacoumDifethialoneWarfarin (0 025%)NodataNodataWarfarin(0.025%)Warfarin (0.054%)No data No dataChlorophacinoneDiphacinoneBromethalinNo data No data7AllevidencesuggestsriskPredominantevidenceofriskEquivocalevidenceofriskAllevidencesuggestslowriskRQs andOpportunityIncident DataConclusionChemicalPrimaryRiskSecondaryRiskPrimary SecondaryUrban/SuburbanPrimary SecondaryBirdsBrodifacoumDifethialoneNo dataWarfarin (0.025%)Warfarin (0 054%)Warfarin(0.054%)ChlorophacinoneDiphacinoneBromethalinNo data No data No dataMammalsBrodifacoumDifethialoneWarfarin (0 025%)NodataNodataWarfarin(0.025%)Warfarin (0.054%)No data No dataChlorophacinoneDiphacinoneBromethalinNo data No data8AllevidencesuggestsriskPredominantevidenceofriskEquivocalevidenceofriskAllevidencesuggestslowriskConclusions from all Lines ofE idvence•MammalsB dif d dif hi l i k–Brodifacoum anddifethialone pose a greater riskrelative to other assessed rodenticides–Risks are similar across the other assessedrodenticides–Risks to mammals expected since rodenticides areintended to kill rodents•Birds–Brodifacoum and difethialone pose a greater riskrelative to other assessed rodenticidesrelativetootherassessedrodenticides9Risks and Mitigation•Assessment of impacts of riskmitigation measures is not based onquantitative estimates of riskreduction•Common sense rationale:C th iti ti bCanthe mitigation measurebereasoned to reduce the potential forildlif ?wildlife exposure?10Risks and Mitigation•Bait station requirement•All NOIC rodenticides for above ground usePlacement of rodenticide bait in a tamper resistant enclosure•Placementofrodenticidebaitinatamperresistantenclosure•Bait is in formulation not expected to be removable from thestation•Exposure reduction effects:Exposurereductioneffects:•Reduction in the size of organisms with access to the baitOnly animals the size of commensal rodents (e.g. no Key deerexposures)•Reduced opportunity for bait encounters for animals not likelyto enter the stations(e.g. birds)•Tier 1 tamper-resistant station are not likely to allow baitaccess to dogs and wildcanids(e.g., kit foxes will not haveaccesstodogsandwild(e.g.,kitfoxeswillnothaveaccess)•Concentrated bait stations represent potential reduction ingeographical extent of bait availability.11Risks and Mitigation•Bait marketing restrictions•Second generation rodenticides (e.g.,Secondgenerationrodenticides(e.g.,brodifacoum and difethialone)•Large package sizes•Sale to professional applicators•Exposure reduction effects:R d ti i thf i l li ti•Reductioninthe non-professionalapplicationrodenticideReduction in the geographic extent of rodenticideapplication•Professional applicators likely to use integratedrodent control approaches (i.e., reduction ofh lt i f d d t )sheltering,foodandwater resources)Limit the attractiveness of use areas to wildlife12Conclusions•Lines of evidence provide a confident riskpicture•There are risks of primary and secondaryTherearerisksofprimaryandsecondarymortality for the NOIC compounds andsubstitutes available on the marketsubstitutesavailableonthemarketThese risks can be managed thro gh the•Theseriskscanbemanagedthroughtheapplication of common sense mitigationrequirements to limit exposure of wildlife inrequirementstolimitexposureofwildlifeina commensal rodent control environment.13